CuCrZrTa alloy wire having a nano-oxide dispersion strengthening phase and a method of manufacturing the same

Abstract

The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. wt％ The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. wt％ The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. wt The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. wt The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. wt The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof. The application discloses a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and a preparation method thereof.

Description

Technical Field

[0001] This invention belongs to the field of alloy preparation technology, and particularly relates to a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and its preparation method. Background Technology

[0002] Tokamak devices are crucial for achieving controlled nuclear fusion. Their internal components, such as magnet windings and divertor cooling pipes, need to operate stably for extended periods under extreme conditions including high temperatures, strong magnetic fields, and intense radiation. Copper alloys, due to their excellent electrical and thermal conductivity and certain strength, hold significant potential for application in tokamak devices.

[0003] However, traditional copper alloys present serious problems at high temperatures. On the one hand, high temperatures intensify the thermal motion of atoms in copper alloys, making dislocations within the alloy more prone to slippage. This results in a sharp drop in high-temperature strength, failing to meet the strength requirements of components during the high-temperature operation of tokamak devices. On the other hand, under strong irradiation, traditional copper alloys exhibit irradiation swelling. This is because irradiation-induced defects (such as vacancies and interstitial atoms) accumulate within the alloy, causing volume expansion. This severely affects the dimensional stability and performance of components, and may even lead to component failure, threatening the safe operation of the tokamak device.

[0004] Currently, although some methods exist to improve the properties of copper alloys, traditional CuCrZr alloys exhibit significant strength degradation above 600℃ (strength <100MPa at 800℃), helium bubble aggregation after neutron irradiation (irradiation swelling rate >5% at 10 dpa), oxide dispersion-strengthened copper, insufficient conductivity (<80% IACS), and poor machinability (fracture elongation <3%). While CuNiBe alloys are used, their high-temperature creep resistance is insufficient (creep strain >1.2% at 800℃ / 100h). It remains difficult to simultaneously and effectively solve the two major problems of rapid strength drop at high temperatures and irradiation swelling. Therefore, there is an urgent need to develop a new type of copper alloy wire and its preparation method to meet the application requirements of extreme environments such as tokamak devices. Summary of the Invention

[0005] The purpose of this invention is to provide a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and its preparation method, so as to solve any of the technical problems in the background art.

[0006] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0007] In some embodiments of this application, a CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase and its preparation method are provided. The wire comprises the following components by weight percentage: Cr: 0.6-1.0wt%, Zr: 0.08-0.12wt%, Ta: 0.03-0.08wt%, Y2O3: 0.2-0.4wt%, B: 0.005-0.02wt%, with the balance being Cu. The phase structure of the wire includes: nano-Cr as a precipitated phase, YTaO dispersion particles, and B segregated grain boundaries.

[0008] In some embodiments of this application, a method for preparing CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase, using the above-mentioned alloy wire, includes the following steps:

[0009] Step 1) Mechanical alloying: Under argon protection, ball mill at a ball-to-material ratio of 10~20:1 and a speed of 300~400 rpm for 15~20 h, and add 0.3~0.8 wt% stearic acid to obtain nanocrystalline powder with a grain size ≤50 nm;

[0010] Step 2) Spark plasma sintering: The nanocrystalline powder is sintered under a vacuum degree ≤5×10 -3 Under Pa, hold at 800~900℃ / 80~120 MPa for 3~10 min to obtain a billet with a relative density ≥99.5%;

[0011] Step 3) Hot extrusion: Extrude the billet into Φ5~8 mm bars at 700~780℃ with an extrusion ratio of 12~16:1;

[0012] Step 4) Warm drawing: The bar from Step 3 is drawn to the target wire diameter in stages and kept warm in stages to obtain CuCrZrTa alloy wire with nano-oxide dispersion strengthening phase.

[0013] In some embodiments of this application, step 4, the staged pulling process, includes:

[0014] Step 4.1) Rough drawing: reduction rate per pass 8~12%, temperature 380~420℃;

[0015] Step 4.2) Fine drawing: 5~8% reduction per pass, temperature 230~270℃.

[0016] In some embodiments of this application, the rough drawing diameter in step 4.1 is Φ5~8 mm-Φ1~1.5 mm, and the fine drawing diameter in step 4.2 is Φ1~1.5 mm-Φ0.1~0.5 mm.

[0017] In some embodiments of this application, the staged insulation process in step 4 includes:

[0018] Step 4.3) First stage: Incubate at 540~560℃ for 0.5~2 h;

[0019] Step 4.4) Second stage: Keep warm at 430~470℃ for 5~15 h.

[0020] In some embodiments of this application, the mechanical alloying parameters in step 1) are: ball-to-material ratio 15:1, rotation speed 350 rpm, and ball milling for 18 h.

[0021] In some embodiments of this application, the discharge plasma sintering parameters in step 2) are: 850℃ / 100 MPa / 5min.

[0022] In some embodiments of this application, step 4, after the phased heat preservation, also includes surface treatment: applying Ta to the heat-preserved bar. + Ion implantation, with ion energy of 25~35 keV and dose of 3~7×10⁻⁶. 16 ions / cm², forming a tritium barrier layer with a thickness ≥200 nm on the surface of the rod.

[0023] Compared with the prior art, the beneficial effects of the present invention are that the present invention suppresses coarsening through Ta-Y2O3 interlocking, resists radiation by B grain boundary segregation, retains nanocrystals through low-temperature sintering, and precisely controls the distribution of precipitated phases through two-stage aging, so that the prepared wire has the characteristics of high strength, strong conductivity and excellent radiation resistance of copper alloy wire, which meets the extreme working conditions of tokamak magnet windings (requiring high conductivity / radiation resistance) and divertor cooling pipes (requiring high temperature resistance / creep resistance). Detailed Implementation

[0024] The specific embodiments of the present invention will be described in further detail below with reference to the examples. These examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0025] To better understand the purpose, structure, and function of this invention, the invention will be further described in detail below with reference to embodiments.

[0026] Example 1

[0027] In this embodiment of the application, the components include the following by weight percentage: Cr: 0.6-1.0wt%, Zr: 0.08-0.12wt%, Ta: 0.03-0.08wt%, Y2O3: 0.2-0.4wt%, B: 0.005-0.02wt%, with the balance being Cu. The phase structure of the wire includes: nano-Cr as a precipitated phase, YTaO dispersed particles, and B segregated grain boundaries.

[0028] The preparation method includes the following steps:

[0029] Step 1) Mechanical alloying (mechanical alloying parameters: ball-to-material ratio 15:1, rotation speed 350 rpm, ball milling for 18 h): Under argon protection, ball mill at a ball-to-material ratio of 10~20:1 and a rotation speed of 300~400 rpm for 15~20 h, add 0.3~0.8 wt% stearic acid to obtain nanocrystalline powder with a grain size ≤50 nm;

[0030] Step 2) Spark plasma sintering (spark plasma sintering parameters: 850℃ / 100 MPa / 5 min): The nanocrystalline powder is sintered under a vacuum of ≤5×10 -3 Under Pa, hold at 800~900℃ / 80~120 MPa for 3~10 min to obtain a billet with a relative density ≥99.5%;

[0031] Step 3) Hot extrusion: Extrude the billet into Φ5~8 mm bars at 700~780℃ with an extrusion ratio of 12~16:1;

[0032] Step 4) Warm drawing: The bar from Step 3 is drawn to the target wire diameter in stages, and heat-preserved in stages. Ta is then applied to the heat-preserved bar. + Ion implantation, with ion energy of 25~35 keV and dose of 3~7×10⁻⁶. 16 By forming a tritium barrier layer with a thickness of ≥200 nm on the surface of the rod, CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase is obtained.

[0033] Step 4, the phased pulling process, includes:

[0034] Step 4.1) Rough drawing: reduction rate per pass 8~12%, temperature 380~420℃;

[0035] Step 4.2) Fine drawing: 5~8% reduction per pass, temperature 230~270℃.

[0036] It should be noted that the rough drawing diameter in step 4.1 is Φ5~8 mm-Φ1~1.5 mm, and the fine drawing diameter in step 4.2 is Φ1~1.5 mm-Φ0.1~0.5 mm.

[0037] It should be further explained that the phased insulation process in step 4 includes:

[0038] Step 4.3) First stage: Incubate at 540~560℃ for 0.5~2 h;

[0039] Step 4.4) Second stage: Keep warm at 430~470℃ for 5~15 h.

[0040] Example 2

[0041] This application adopts some of the technical features from the above embodiments, wherein the alloy design is as follows:

[0042] Ingredient system (wt%):

[0043] Cr 0.8, Zr 0.1, Ta 0.05, Y2O3 0.3, B 0.01, balance Cu;

[0044] Phase structure design:

[0045] Nanoscale Cr precipitates (515 nm)

[0046] YTaO dispersed particles (25nm)

[0047] B-segregation grain boundaries (GB coverage > 60%)

[0048] Powder metallurgy stage

[0049] High-energy ball milling: Argon protection, ball-to-material ratio 15:1, rotation speed 350 rpm, addition of 0.5 wt% stearic acid, ball milling for 18 hours to obtain nanocrystalline powder (crystal size ≈ 35 nm).

[0050] densification treatment

[0051] Spark plasma sintering (SPS): 850℃ / 100MPa / 5min, vacuum degree ≤5×10 -3 Pa, relative density ≥99.8%

[0052] Deformation heat treatment

[0053] Hot extrusion: Extruded at 750℃ into Φ6mm bars (extrusion ratio 14:1)

[0054] Multi-pass temperature drawing: Rough drawing (Φ6→Φ1mm): 1012% reduction per pass, 400℃; Fine drawing (Φ1-Φ0.2mm): 68% reduction per pass, 250℃;

[0055] Tiered time limits:

[0056] First stage: 550℃×1h (Cr phase precipitation); Second stage: 450℃×10h (YTaO cluster stabilization);

[0057] Surface treatment

[0058] Ion implantation of Ta+ (energy 30keV, dose 5×10⁻⁶) 16 (ions / cm²) to form a surface tritium barrier layer;

[0059] Ta / Y2O3 synergistic effect: Ta inhibits the coarsening of Y2O3 particles, while Y2O3 pins Ta atoms;

[0060] B element segregates at grain boundaries, reducing radiation damage (confirmed by molecular dynamics simulations).

[0061] Low-temperature SPS (150°C lower than traditional HIP) preserves the nanostructure;

[0062] Precise control of precipitate distribution through graded aging;

[0063] Three-dimensional interlocked nano-precipitation network (confirmed by APT three-dimensional reconstruction).

[0064] Performance data

[0065] Test Project Test Results Test Standards room temperature tensile strength 580MPa ASTME8 800℃ tensile strength 380MPa Room temperature conductivity 93% IACS IEC60468 15 dpa irradiation swelling rate 1.2% ISO 12772 Thermal fatigue life (500-900℃) >8000 times GB / T15248

[0066] Example 3

[0067] This application adopts some of the technical features from the above embodiments. Taking Φ0.5mm wire as an example, its microstructure is as follows:

[0068] Average grain size: 120 nm;

[0069] Cr precipitated phase density: 5.8 × 10²² m³ -3 ;

[0070] performance:

[0071] Elongation at break: 18%

[0072] Creep rate at 1000℃ / 100h: 2.3×10 -8 s -1

[0073] Copper alloy wire:

[0074] High temperature performance: Strength ≥350MPa at 800℃ (3 times higher than traditional CuCrZr)

[0075] Radiation resistance: Swelling rate <1.5% after 15 dpa irradiation.

[0076] Electrical conductivity balance: room temperature conductivity ≥ 92% IACS, yield strength ≥ 550 MPa

[0077] Technology Comparison

[0078] performance CuCrZr ODSCu This invention 800℃ strength 85MPa 220MPa 380MPa Irradiation swelling rate (15 dpa) 5.5% 3.2% 1.2% electrical conductivity 75% IACS 65% IACS 93% IACS Minimum wire diameter 0.3mm 0.5mm 0.1mm

[0079] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0080] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0081] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0082] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase, characterized in that, The wire comprises the following components by weight percentage: Cr: 0.6-1.0 wt%, Zr: 0.08-0.12 wt%, Ta: 0.03-0.08 wt%, Y2O3: 0.2-0.4 wt%, B: 0.005-0.02 wt%, with the balance being Cu. The phase structure of the wire includes: nano-Cr as precipitated phase, YTaO dispersed particles, and B segregated grain boundaries. The preparation method of the CuCrZrTa alloy wire with nano-oxide dispersion strengthening phase includes the following steps: Step 1) Mechanical alloying: Under argon protection, ball mill at a ball-to-material ratio of 10~20:1 and a speed of 300~400 rpm for 15~20 h, and add 0.3~0.8 wt% stearic acid to obtain nanocrystalline powder with a grain size ≤50 nm; Step 2) Spark plasma sintering: The nanocrystalline powder is sintered under a vacuum degree ≤5×10 -3 Under Pa, hold at 800~900℃ / 80~120MPa for 3~10 min to obtain a billet with a relative density ≥99.5%; Step 3) Hot extrusion: Extrude the billet into Φ5~8 mm bars at 700~780℃ with an extrusion ratio of 12~16:1; Step 4) Warm drawing: The bar from Step 3 is drawn to the target wire diameter in stages and kept warm in stages to obtain CuCrZrTa alloy wire with nano-oxide dispersion strengthening phase.

2. The CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase according to claim 1, characterized in that, Step 4, the phased pulling process, includes: Step 4.1) Rough drawing: reduction rate per pass 8~12%, temperature 380~420℃; Step 4.2) Fine drawing: 5~8% reduction per pass, temperature 230~270℃.

3. The CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase according to claim 2, characterized in that, In step 4.1, the diameter of the wire after rough drawing is Φ1~1.5mm, and in step 4.2, the diameter of the wire after fine drawing is Φ0.1~0.5mm.

4. The CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase according to claim 1, characterized in that, The phased insulation process in step 4 includes: Step 4.3) First stage: Incubate at 540~560℃ for 0.5~2 h; Step 4.4) Second stage: Keep warm at 430~470℃ for 5~15 h.

5. The CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase according to claim 1, characterized in that: Step 1) The mechanical alloying parameters are: ball-to-material ratio 15:1, rotation speed 350 rpm, and ball milling for 18 h.

6. The CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase according to claim 1, characterized in that: Step 2) The discharge plasma sintering parameters are: 850℃ / 100 MPa / 5 min.

7. The CuCrZrTa alloy wire with a nano-oxide dispersion strengthening phase according to claim 1, characterized in that: Step 4, after the phased heat preservation, also includes surface treatment: applying Ta to the heat-preserved bar. + Ion implantation, with ion energy of 25~35 keV and dose of 3~7×10⁻⁶. 16 ions / cm², forming a tritium barrier layer with a thickness ≥200 nm on the surface of the rod.